Field of the Invention
The invention relates to a multichannel electro-optical assembly containing a first array of electro-optical transducers for electro-optical conversion of radiation having a first light wavelength and at least one further array of electro-optical transducers for electro-optical conversion of radiation having at least one second light wavelength different from the first light wavelength. A plurality of optical waveguides and a deflection device for optically coupling in each case an electro-optical transducer of the first array and of the further array, on one side, and an optical waveguide, on the other side, are provided. It lies in the field of electro-optical data transmission, in which electrical information converted into optical signals (e.g. infrared light signals) by a transmitter passes via a suitable optical waveguide to an optical receiver. The receiver converts the received signals back into electrical signals. Such transmitters and receivers are hereinafter generally also designated as electro-optical transducers.
Thus, in the context of the present invention, a transducer is to be understood as an assembly which, given corresponding electrical driving, outputs (transmitter) an optical signal (radiation) or, upon application of an optical signal, generates (receiver) a corresponding electrical signal. The actual electro-optical signal conversion takes place in a radiation-emitting region or a radiation-sensitive region. These regions or areas are generally also designated as optically active zones. Examples of suitable transducers are laser diodes or photodiodes.
In the context of the invention, an optical waveguide is to be understood as any element suitable for the spatially delimited, guided forwarding of an optical signal, e.g. prefabricated optical waveguides which can be combined in a parallel fashion in a so-called optical waveguide rhythm.
An assembly of the generic type is described in U.S. Pat. No. 5,416,624. The assembly has a transmitting array and a receiving array of electro-optical transducers that are coupled via a deflection device with optical waveguides. In this case, the deflection device has a configuration of wave-selectively coated lenses which have the effect that radiation of a first wavelength is coupled from the transmitting array into the optical waveguides and radiation of a second wavelength which is coupled out from the optical waveguides is conducted onto a receiving array.
The paper xe2x80x9c1-Gbyte/sec array transmitter and receiver modules for low-cost optical fiber interconnectionxe2x80x9d by T. Nagahori et al. from 1996 IEEE, Electronic Components and Technology Conference, pages 255 to 258, describes an assembly having a plurality of electro-optical transducers configured as optical receivers. Each receiver is assigned to an optical waveguide end of a multichannel optical waveguide rhythm (xe2x80x9coptical fiber arrayxe2x80x9d). The radiation-sensitive region of each transducer is optically coupled via a mirror to the light-guiding core of the respective optical waveguide. The sensitivity of the transducers is limited to a single specific light wavelength that is transmitted by the optical waveguides.
Optical data transmission technology is increasingly required to increase the data transmission capacity while simultaneously reducing and simplifying the individual components and minimizing the structural space required. This has led in particular to the development of multichannel transmission systems.
It is accordingly an object of the invention to provide a multichannel electro-optical assembly which overcomes the above-mentioned disadvantages of the prior art devices of this general type, which significantly increases the transmission capacity of the multichannel electro-optical assembly in the simplest manner without increasing the structural space.
With the foregoing and other objects in view there is provided, in accordance with the invention, a multichannel electro-optical assembly. The assembly contains a first array having electro-optical transducers for electro-optical conversion of radiation with a first light wavelength and at least one second array having electro-optical transducers for electro-optical conversion of radiation having at least one second light wavelength being different from the first light wavelength. The at least one second array is disposed parallel to the first array. A plurality of optical waveguides are provided. A deflection device for optically coupling in each case one of the electro-optical transducers of the first array and of the at least one second array to one of the optical waveguides. The deflection device has at least two reflecting surfaces disposed parallel to one another and each of the two reflecting surfaces is associated respectively with one of the first array and the at least one second array so that into each of the optical waveguides the radiation of the first wavelength and the radiation of the second wavelength is able to be coupled in or out or radiation of the first wavelength is coupled in and radiation of the second wavelength is coupled out.
Accordingly, it is provided that at least two arrays of electro-optical transducers are disposed parallel to one another and the deflection device has at least two reflecting surfaces which are disposed parallel and are respectively assigned to an array. The effect thereby achieved is that, into each optical waveguide, radiation of the first wavelength and radiation of the second wavelength is coupled in or out or radiation of the first wavelength is coupled in and radiation of the second wavelength is coupled out.
An essential advantage of the assembly according to the invention is that, by virtue of the transmission with different light wavelengths, which is superposed on a plurality of parallel, physically separate channels (wavelength division multiplex), quite a considerable increase in the transmission capacity can be realized without resulting in an increase in the requisite structural space or the requisite number of transmission channels.
Provided that radiation both of the first wavelength and of the second wavelength is coupled into each optical waveguide or radiation both of the first wavelength and of the second wavelength is coupled out from each optical waveguide. The invention enables multichannel transmission or reception operation via a plurality of separate optical waveguides in wavelength division multiplex operation.
In a preferred, particularly compact refinement of the invention, it is provided that at least one of the reflecting surfaces disposed parallel reflects radiation having the first light wavelength and transmits radiation having the second light wavelength.
With regard to the orientation and mounting, further advantages are afforded in a refinement of the assembly according to the invention in which the optical axes of the transducers, on the one hand, and the optical axes of the optical waveguides, on the other hand, are at right angles to one another, and that the transducers run in parallel rows.
Particularly effective coupling with a high coupling efficiency between the optical waveguides and the assigned transducers can be achieved, according to a preferred development of the invention, by virtue of the fact that the deflection device has beam-shaping elements on at least one coupling surface facing the transducers or the optical waveguides.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a multichannel electro-optical assembly, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.